I agree; the second heuristic doesn't apply particularly well to this scenario. Some terminal values seem to come from a part of the brain which isn't open to introspection, so I'd expect them to arise as a result of evolutionary kludges and random cultural influences rather than necessarily making any logical sense.

The thing is, once we have a value system that's reasonably stable (i.e. what we want is the same as what we want to want) then we don't want to change our preferences even if we can't explain where they arise from.